Daniel Berehulak/Getty ImagesNaga Sadhus, naked Hindu holy men, walk in procession after having bathed on the banks of the holy rivers Ganges, Yamuna, and the mythical Saraswati, during the Maha Kumbh Mela on February 10, 2013 in Allahabad, India.

LEGEND HOLDS THAT KUMBH MELA originated in an ancient battle between gods and demons for the elixir of immortality. And even today, Kumbh Mela absolutely lives up to those larger-than-life origins.

Four Indian cities (Hardiwar, Allahabad, Nashik, Ujjain) take turns hosting this Hindu festival at somewhat irregular intervals, which are determined by the positioning of the Sun, the Moon, and Jupiter. Each location plays host once every 12 years.

The mass gathering allows ordinary Hindus to interact with and receive religious rites from the sadhus (holy men) that attend. Moreover, Kumbh Mela allows both sadhus and civilians to bathe in the festival site’s holy river, thereby cleansing themselves of sin.

As you might guess for a festival borne of divine battle and celebrated according to the alignment of celestial bodies, Kumbh Mela is positively gargantuan. More than 120 million people attended the 2013 Kumbh Mela in Allahabad over its two-month duration, with 30 million attending on the festival’s holiest day alone. Those figures still may not give you the full scope of just how big this festival is, so maybe these photos will:

Kumbh Mela's crucial moment is the bathing in the sacred rivers. Above, sadhus run into the Sangham (the confluence of the the Yamuna and Ganges rivers) during the Kumbh Mela in Allahabad on January 14, 2013. Hundreds of thousands of Hindu pilgrims led by naked, ash-covered holy men streamed into the sacred river during the festival.ROBERTO SCHMIDT/AFP/Getty Images

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The festival's most auspicious bathing day is Makar Sankranti, at which time enormous crowds will gather at the river's edge —above, in January 2013 in Allahabad.Daniel Berehulak/Getty Images

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Among all the bathers, the most revered are the naga sadhu (naked holy man), who go nude to show their separation from the material world. Above, a naga sadhu dries his hair after taking a holy bath at Sangham in Allahabad.STRDEL/AFP/Getty Images

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In addition to leading the bathing charge, sadhus will ritualistically paint their bodies, smoke pipes, and play traditional musical instruments.Sanjay Kanojia/AFP/Getty Images

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Before sadhus take part in any rituals, however, they must first gather together and be initiated in a ceremony known as diksha (above).Sanjay Kanojia/AFP/Getty Images

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After initiation and before bathing, sadhus walk in a procession toward the holy river.Sanjay Kanojia/AFP/Getty Images

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At the banks of the holy river, naga sadhus perform the aarti ceremony, a prayer ritual in which a sacrifice is offered to the gods.Daniel Berehulak/Getty Images

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Once in the holy river, sadhus will often shout and brandish swords as a way to mark and celebrate the beginning of the mass bathing.ROBERTO SCHMIDT/AFP/Getty Images

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A Bihari Hindu priest, smeared with colored powder, looks on after the completion of a ritual at the Sangham.Sanjay Kanojia/AFP/Getty Images

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Naga sadhus run to bathe in the holy Ganges river during the auspicious bathing day of Makar Sankranti.Daniel Berehulak/Getty Images

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Sadhus smoke at their camp near the ritual site at Sangham.Mario Tama/Getty Images

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A naga sadhu bathes in the Ganges river during the auspicious bathing day of Makar Sankranti.Daniel Berehulak/Getty Images

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A sadhu beats on drums as he and others like him march toward the Sangham.Sanjay Kanojia/AFP/Getty Images

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Hindu priests perform an aarti ceremony on the banks of the Ganges river.Daniel Berehulak/Getty Images

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Hindu devotees bathe on the banks of the Sangham.Daniel Berehulak/Getty Images

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While millions may bathe in the Ganges for Kumbh Mela, its waters can be extremely polluted. Above, men search for coins and gold amid the refuse.Sanjay Kanojia/AFP/Getty Images

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Devotees pray while bathing in the Sangham.ROBERTO SCHMIDT/AFP/Getty Images

Some sadhus use human bones in their rituals and healing rites.Sanjay Kanojia/AFP/Getty Images

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A naga sadhu smokes a chillum, a traditional clay pipe, at his camp.RAVEENDRAN/AFP/Getty Images

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In addition to their clothing (or lack thereof) and body painting, many sadhus distinguish themselves with long dreadlocks.Sanjay Kanojia/AFP/Getty Images

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Naga sadhus bathe in the waters of the Ganges during Makar Sankranti.Daniel Berehulak/Getty Images

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Hindu devotees walk through a dust storm at the Sangham.Sanjay Kanojia/AFP/Getty Images

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Thousands of Hindu devotees make their way across the pontoon bridges spanning the Ganges.JOHN MACDOUGALL/AFP/Getty Images

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Naga sadhus charge into the Ganges river during Makar Sankranti.Daniel Berehulak/Getty Images

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A devotee offers prayers to the Sun God at Sangham.Sanjay Kanojia/AFP/Getty Images

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A Indian woman makes mud stoves near the banks of the Ganges for use during Kumbh Mela.Sanjay Kanojia/AFP/Getty Images

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Hindu pilgrims gather to bathe at sunrise at the Sangham.Mario Tama/Getty Images

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Devotees' tents line the river's edge.Sanjay Kanojia/AFP/Getty Images

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A Hindu woman prays on the shore of the holy river.ROBERTO SCHMIDT/AFP/Getty Images

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Hundreds of thousands of Hindu devotees crowd the banks of the Ganges.JOHN MACDOUGALL/AFP/Getty Images

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After the festival ends, massive amounts of refuse can be left behind. Above, a man collects recyclable material from camping grounds near the Sangham following the conclusion of Kumbh Mela.Sanjay Kanojia/AFP/Getty Images